Physical layer key generation (PLKG) is a promising technology to obtain symmetric keys between a pair of wireless communication users in a plug-and-play manner. The shared entropy source almost entirely comes from the intrinsic randomness of the radio channel, which is highly dependent on the wireless environment. However, in some static wireless environments, the intrinsic randomness of wireless channel is hard to be guaranteed. Very recently, thanks to reconfigurable intelligent surfaces (RISs) with their excellent ability on electromagnetic wave control, the wireless channel environment can be customized. In this article, we overview the RIS-aided PLKG in a static indoor environment, including its potential application scenarios, channel model and hardware architectures. Then, we analyze the design challenges of RIS-aided PLKG, including channel reciprocity, RIS switch speed and RIS deployment via proof-of-concept experiments on a RIS-aided PLKG prototype system. In particular, our experimental results show that the key generation rate is 15-fold higher than that without RIS in a static indoor environment. Next, we design a RIS flip attack via a prototype experiment and discuss its possible attack-defense countermeasures. Finally, several conclusions and future directions are identified.
翻译:物理层钥匙生成( PLKG) 是一对无线通信用户之间获得对称密钥的一个很有希望的技术。 共享的英特罗比源几乎完全来自无线电频道的内在随机性, 高度依赖无线环境。 但是, 在某些静态无线环境中, 无线频道的内在随机性很难得到保证。 最近, 由于可重新配置的智能表面( RIS) 在电磁波控制方面能力极强, 无线频道环境可以定制化。 在文章中, 我们概述了静态室内环境中的RIS辅助的PLKG, 包括其潜在的应用情景、 频道模型和硬件结构。 然后, 我们分析了受RIS辅助的PLCG的设计挑战, 包括频道对等性、 RIS 开关速度和通过对立测试测试测试测试的RIS 原型系统部署。 特别是, 我们的实验结果表明, 在静态室内环境中, 关键生成率比没有RIC高出15倍。 下一步, 我们设计了RIS 反向反向攻击, 最终通过原型研究, 讨论可能的攻击结论。